1. Technical Field
The subject disclosure relates to minimally invasive surgical procedures and apparatus and, more particularly, to instruments and methods for performing heart valve replacement surgery.
2. Background of Related Art
The diagnosis and treatment of coronary disease and related conditions often requires repair or replacement of the valves located within the heart. Various factors, such as, for example, calcification, may result in the mitral or aortic valves becoming impaired or functionally inoperative requiring replacement. Where replacement of a heart valve is required, in general, the dysfunctional valve is cut out and replaced with either an artificial, synthetic heart valve or a harvested porcine heart valve. The replacement valve is typically sutured in place of the original valve.
Access to the heart in a patient""s thoracic cavity is achieved by making a longitudinal incision in the chest. This procedure, referred to as a median sternotomy, includes cutting through the sternum and forcing the two opposing halves of the rib cage to be spread apart allowing access to the thoracic cavity and thus the heart.
Suitable instruments for spreading and holding apart the rib cage are marketed by United States Surgical Corporation, Norwalk, Conn. These instruments include, for example, Mini-CABG* retractors and related accessories. The Mini-CABG* universal retractor includes a substantially planar base having an opening which can be positioned on the patient such that the opening overlies the incision at the operative site. Mini-CABG* retractors are slidably mounted on the base and are provided to spread apart the rib cage halves and engage and retract obstructing tissue. The base may also be provided with surgical instruments which can be used to stabilize or manipulate the heart during surgery.
Once access to the thoracic cavity has been achieved, surgery on the heart to effect valve replacement may be performed. During some procedures, the heart beat is arrested by infusion of a cardioplegic fluid, such as potassium chloride (KCl), to paralyze the myocardium while blood flow circulation is maintained through known heart bypass techniques. Alternatively, the heart is allowed to beat to maintain circulation, while a localized area of the heart, on which surgery is to be performed is locally immobilized by various instruments.
The heart is incised and the defective valve is cut away leaving a surrounding area of locally tougher tissue. Known heart valve replacement techniques typically include individually passing sutures through the tough tissue by hand to form an array of sutures. Free ends of the sutures are extended out of the thoracic cavity and laid, spaced apart, on the patient""s body. The free ends of the sutures are then individually threaded through an edge around the circumference of the replacement valve or a supporting cuff. This is also typically accomplished by hand. Once all sutures have been run through the valve, all the sutures are pulled up taut and the valve is slid or xe2x80x9cparachutedxe2x80x9d down, by hand, into place adjacent the tough tissue. Thereafter, the replacement valve is secured in place using the sutures. Since the conventional heart valve replacement techniques are exclusively manual procedures, they are typically time consuming and difficult.
Where replacement is performed utilizing an artificial valve hand held instruments in the form of a stick may be affixed to the valve and used to manipulate the replacement valve into place. The commercially available replacement valves are typically provided with a detachable holder structure which can be engaged by the hand tools.
While the above described procedures are sufficient to successfully position a heart valve within the heart, they are particularly time consuming. A more suitable apparatus would be desirable for maintaining the valve in a position such that a plurality of sutures may simultaneously pierce a cuff of the heart valve and thereafter assist in placement of the heart valve in the heart to allow it to be secured in place. Therefore, a need exists for apparatus and procedures of quickly and efficiently positioning and affixing artificial heart valves within the heart.
There are provided various embodiments of systems and methods for installing a synthetic, artificial heart valve within a patient. The first system generally includes a plurality of sutures, each suture having a staple attached to a distal end thereof; a surgical stapler for radially discharging the staples into a heart at a location adjacent a site for installing the heart valve; a support assembly for releasably supporting the plurality of sutures; and a heart valve setter assembly, the heart valve setter assembly being operable to move the heart valve into position within the site in the heart.
Preferably the plurality of sutures also include a plurality of needles attached to a proximal end thereof. The needles may then be secured within a plurality of grooves on an inner surface of the support assembly with the pointed ends pointed proximally to facilitate insertion through a cuff of a replacement heart valve, and into a ring shaped needle guard mounted on the support assembly. The support assembly preferably includes a plurality of legs and a ring member, wherein the ring member is configured to interconnect the plurality of legs at a proximal end thereof.
The heart valve setter assembly, which includes a heart valve holder assembly and a heart valve setting instrument, may be mounted on the support assembly to lower the heart valve replacement into a predetermined location within the heart. The heart valve holder assembly includes a shaft, a handle connected to a proximal end of the shaft, and a heart valve holder connected to a distal end of the shaft. The heart valve setting instrument includes a shaft having a knurled proximal portion and a needle grasper connected to a distal end of the shaft, and is slidably mounted on the heart valve holder assembly. The heart valve is moved along the sutures into position within the predetermined site in the heart.
A method of installing a heart valve within a patient is provided and generally includes the steps of accessing a site within a heart from which a natural heart valve has been removed; positioning a surgical stapler within the site; discharging a plurality of staples, having sutures attached thereto, from the surgical stapler into the heart; lowering the heart valve along the sutures into position within the site in the heart; and securing the heart valve to the heart with the sutures.
The method of installing a heart valve within a patient as described above, is preferably provided wherein the sutures have needles attached to an end opposite the staples. The method further includes the step of securing the sutures at a location above the site within the heart with a support assembly. Also prior to the step of lowering the heart valve along the sutures the sutures are threaded through a cuff of the heart valve to facilitate lowering the heart valve along the sutures into position within the site in the heart. Lastly, prior to the step of securing the heart valve to the heart, the heart valve installation assembly is removed from the accessed site.